1. Field of the Invention
The present invention relates to package structures and fabrication methods thereof, and more particularly, to a light emitting diode (LED) package structure and a fabrication method thereof.
2. Description of Related Art
Since LEDs have advantages of long lifetime, low power consumption and short response time and do not have idling time, the application of the LEDs is increasingly expanded. Particularly, LEDs of different colors have been developed and widely adopted in lighting applications, and conventional cold cathode bulbs, halogen bulbs or incandescent bulbs are being replaced by the LEDs so as to meet the energy saving and carbon reducing trend.
Currently, LED structures with adjustable color temperatures have been developed to extend the application of the LEDs. As disclosed by U.S. Pat. No. 7,564,180, one method for achieving such a structure involves using LEDs of at least two different colors in combination with at least a type of phosphor, which, however, results in a complicated fabrication process and high cost.
FIG. 1 shows a conventional LED structure with adjustable color temperature. Referring to FIG. 1, a carrier 10 having two recesses 100a, 100b is provided, wherein each of the recesses 100a, 100b has electrical contacts 11 and a silver paste layer 12 formed on the bottom thereof. LED chips 13 of the same type are disposed on the silver paste layers 12 in the recesses 110a, 100b and electrically connected to the corresponding electrical contacts 11 through bonding wires 14, respectively. Then, phosphors 15a, 15b of two or more different color temperatures are coated on the LED chips 13 in the recesses 100a, 100b, respectively, and the luminous intensity of the LED chips 13 is adjusted so as to emit light of different color temperatures.
However, the above-described fabrication process requires a plurality of recesses and needs to coat the phosphors at least two times, thereby complicating the fabrication process and increasing the fabrication cost and the package size.
Therefore, there is a need to provide an LED package structure and a fabrication method thereof so as to overcome the above-described drawbacks.